This paper argues Japanese letter has undergone these stages that are using Chinese letter, absorbing Chinese letter, writing special Japanese letter by using Chinese letter, writing Chinese letter by using Japanese language, Wan Ye cryptonym, Ping Pian cryptonym, and complex type of writing. On the one hand, the process of absorbing Chinese letter and creating Japanese language embodies the competence and tradition of Japanese; on the other hand, it confirms the influence of Chinese language on foreign language.